1. Field of the Disclosure
Embodiments disclosed herein relate generally to thermosetting systems for dampening vibrations. More specifically, embodiments disclosed herein relate to thermosetting systems for dampening vibrations at high temperatures.
2. Background
Dampener materials commonly used in the transportation and aerospace industry include rubber materials, bituminous pads, and other similar materials. These materials are typically only effective at dampening vibrations at low temperatures, most often at room temperature.
However, parts used in the transportation and aerospace industry are often subjected to mechanical vibrations at high temperatures. In particular, vibration dampening at temperatures in excess of 150° C. is very difficult to achieve.
There exists a need for thermoset compositions useful for vibration dampening at elevated temperatures. As illustrated by the following references, there exists various materials having high glass transition temperatures or that are stable at high temperatures.
For example, high temperature thermoplastic compositions are disclosed in “Creep behaviour of polymer blends based on epoxy matrix and intractable high Tg thermoplastic,” C. Gauthier et al., Polymer International (2004), 53(5), pages 541-549. Compositions disclosed include a dispersion of crosslinked thermoset epoxy-amine in a thermoplastic polyetherimide matrix. Similarly, high temperature (>140° C.) corrosion protective coatings including high Tg thermoplastic and thermoset epoxyamine monomers are disclosed in “Innovative pipe coating material and process for high temperature fields,” Sauvant-Maynot et al., Oil & Gas Science and Technology (2002), 57(3), pages 269-279.
A material for microelectronics packaging having a low dielectric constant and high thermal stability is disclosed in “Polyquinoline/bismaleimide blends as low-dielectric constant materials,” Nalwa et al., Proceedings—Electrochemical society (1999), 98-6 (Electrochemical Processing in ULSI Fabrication I and Interconnect and Contact Metallization: Materials, Processes, and Reliability), pages 135-144.
A hot-melt processable thermoset composition prepared by blending tetraglycidyl-4,4′-diaminodiphenylmethane/4,4′-diaminodiphenyl sulfone epoxy resin and a high Tg thermoplastic polyimide is disclosed in “Polyimide-modified epoxy system: time-temperature-transformation diagrams, mechanical and thermal properties,” Biolley et al, Polymer (1994), 35(3), pages 558-564. The consequences of the thermoplastic incorporation, such as a polyimide concentration of 10 weight percent, were a slight increase in Tg and limited improvements in stress at rupture and strain-energy release rate Glc compared to the unmodified epoxy matrix.
Thermoplastic/thermosetting polyimide blends containing polyimide PI 2080 (I) [62181-46-8] and N,N′-(methylenedi-p-phenylene)bismaleimide are disclosed in “Preparation and characterization of thermoplastic/thermosetting polyimide blends,” Yamamoto et al, SAMPE Journal (1985), 21(4), pages 6-10. The blends are heated at temperatures greater than 180° C. to form a co-continuous composite thermoplastic-thermoset structure having high glass transition temperatures (greater than 300° C.). Carbon fabric- and glass fabric-reinforced blends maintained their mechanical properties at temperatures less than 260° C.
EP 1225203 discloses use of thermoplastic additives with high glass transition temperatures (140° C. to 220° C.) in thermosetting compositions. Modified polyoxyphenylenes dissolved in styrene were used in glass fiber-reinforced thermosetting compositions based on unsaturated maleic acid resins.
U.S. Pat. Nos. 6,103,810 and 6,268,425 disclose alloys formed from mixed alkali pyrophosphate glass and high temperature organic thermoplastic or thermosetting polymers having working temperatures which are compatible with that of the glass and/or the precursor glass. The glass and polymers are combined at the working temperature to form an intimate mixture of an essentially uniform, fine grained microstructure.
EP 382575 discloses a co-continuous thermoplastic-thermoset crosslinked blend, such as a siloxane-polyimide prepared by the reaction of bis[4-(3-aminophenoxy)phenyl]sulfone, 9,9-bis(aminophenyl)fluorine, an amine-terminated polydimethylsiloxane, and biphenyltetracarboxylic dianhydride blended with resorcinol diglycidy ether, phenol novalac resin, and 4,4′-diaminodiphenyl sulfone, the mixture of which is cured at 130° C. for 2 hours and at 180° C. for two hours. Fiber reinforced structures formed from the cured resins disclosed have a glass transition temperature (Tg) of at least 120° C., among other properties.
JP 2005126473 discloses an ethylene copolymer rubber composition having good dynamic fatigue at high temperatures. The heat-resistant dampening rubber composition is obtained by premixing of (b) 50-85 wt. % of a hydrogenated nitrile rubber having ≦80 iodine value with (c) 50-15 wt. % of zinc methacrylate [with the proviso that the sum total of the (b) and (c) is 100 wt. %]. The resultant mixture in an amount of 2-200 parts by weight is then mixed with (a) 100 parts by weight of an ethylene-α-olefinic copolymer rubber and 2-20 parts by weight of an organic peroxide cross-linking agent so as to make (c) the zinc methacrylate which is used as a reinforcing agent unevenly distributed in (b) the hydrogenated nitrile rubber having ≦80 iodine value.
JP 11071568 discloses adhesive compositions including (A) 0.1-20 wt. % of a non-liquid crystalline resin such as a nylon resin, e.g. nylon 66, nylon 6 or a nylon copolymer containing the nylon 66 or nylon 6 as a main component, (B) 80-99.9 wt. % of a liquid-crystalline resin, and preferably (C) an inorganic filler having a weight-average major axis or weight-average fiber length of 100-400 μm, a ≦60 μm major axis or fiber length filler content of 10-50 wt. % based on the total amount of all the fillers, and an average thickness or average fiber diameter of 5-15 μm in an amount of 5-300 parts per 100 parts by weight of the total amount of the components A and B. The compositions are high in strength, excellent in moldability, heat resistance, toughness, oil resistance, gasoline resistance, abrasion resistance, molded product surface smoothness, high temperature rigidity, dimensional stability and vibration-dampening characteristics and high in strength by including a non-liquid crystalline resin and a liquid-crystalline resin in a specific ratio.
U.S. Pat. No. 6,822,067 discloses polycyanates and polycyanate/epoxide combinations that are useful as laminating resins. The resulting thermosetting polycyanate copolymers have a high proportion of triazine structures and glass transition temperatures up to about 200° C.
Compositions or blends having high glass transition temperature materials or materials that are stable at high temperatures may be described in the references above. However, there is a lack of vibration dampening materials that are effective at elevated temperatures.
Accordingly, there exists a need for thermoset dampener materials effective a dampening vibrations when used at elevated temperatures.